Structure and Regulation of Pol II Elongation Complexes

这个项目的长期目标是确定在高等真核生物中导致RNA聚合酶II停止和终止的转录复合体中的相互作用。转录抑制或终止有助于真核生物的基因调控，但其潜在的机制尚不清楚。为了了解这些机制，需要更好地了解RNA聚合酶II转录延伸复合体的结构，这两个复合体都位于通常延伸有效的停滞位置。将开发方法来生产定义的延长复合体，该复合体包含纯RNA聚合酶II或RNA聚合酶II，其携带在启动子启动过程中获得的修饰和辅助因子。这两种类型的定义延伸复合体将被分离出来，并使用各种试剂来探测它们的结构，这些试剂可以揭示它们内部的RNA和DNA链的配置。将进行实验以测试两种转录抑制模型：1)转录构型改变会导致转录抑制；2)转录抑制是由DNA分子弯曲或构象改变引起的。这项研究将对RNA聚合酶如何将基因(DNA)中的信息转录成表达遗传信息所需的RNA产品产生新的见解。

The long-range goal of this project is to define the interactions in the transcription complex that cause arrest and termination by RNA polymerase II in higher eukaryotes. Transcriptional arrest or termination contributes to gene regulation in eukaryotes, but the underlying mechanisms are unknown. To understand these mechanisms, a much better appreciation of the structure of RNA polymerase II transcription elongation complexes, both at arrest sites where elongation normally is efficient, will be required. Methods will be developed to produce defined elongation complexes that contain either pure RNA polymerase II or RNA polymerase II that carries the modifications and auxiliary factors it acquires during initiation at a promoter. Both types of defined elongation complexes will be isolated and their structures probed using a variety of agents that can reveal the configuration of RNA and DNA strands within them. Experiments will be performed to test two models for transcriptional arrest; 1) that altered configuration of the transcript produces arrest and 2) that arrest is caused by bent, or conformationally altered, DNA molecules. %%% This study will produce new insight into how RNA polymerase transcribes the information in genes (DNA) to an RNA product which is required to express genetic information.